1. Field of the Invention
The present invention relates to an image processing device and method and a recording medium, and in particular, to an image processing device which corrects defective portions within an image as represented by image information, to an image processing method which is applicable to the image processing device, and to a recording medium on which is recorded a program for making a computer function as an image processing device.
2. Description of the Related Art
There are cases in which scratches are formed on an emulsion surface or back surface (the reverse surface from the emulsion surface) of a photographic film due to how the photographic film has been handled. In a case in which a scratch is formed in a place on the photographic film corresponding to an image-recorded region, when the image which is recorded on the photographic film is output (is recorded onto an image recording material such as a photographic printing paper, or is displayed on a display means such as a display), there are many cases in which (although it depends upon the extent of the scratch) the scratch formed in the photographic film is clearly visible on the output image as a defective portion such as a low density streak or a white streak or the like. Further, in cases in which foreign matter such as dust or the like adheres to the surface of the photographic film, the foreign matter is clearly visible as a defective portion.
In a planar exposure type photographic printing device, which irradiates light onto a photographic film and irradiates the light which has passed through the photographic film onto photographic printing paper so as to expose and record the image onto the photographic printing paper, as a countermeasure to scratching of the photographic film, a diffusion plate is disposed between the light source and the photographic film, and the light which is scattered by the diffusion plate is irradiated onto the photographic film. However, with this technique, it is difficult to eliminate the defective portions from the output image (the image which is exposed and recorded on the photographic printing paper), and the defects are merely mitigated slightly (i.e., are merely made to be slightly less noticeable).
A technique which is applicable to image reading devices which are structured to read, by a reading sensor such as a CCD, an image recorded on a photographic film is disclosed in Japanese Patent Application Laid-Open (JP-A) No. 11-75039, which discloses reading a photographic film for at least four wavelength ranges, including three wavelengths in the visible light region and one wavelength in the invisible light region (e.g., the infrared region or the ultraviolet region). On the basis of information obtained by reading in the invisible light region, the image information which is obtained by reading in the visible light region is corrected.
For light in the visible light region, the transmitted light amount varies in accordance with the density of the image recorded on the photographic film. Further, at places where scratches are formed in or foreign matter adheres to the photographic film, the transmitted light amount of the light in the visible light region varies due to light being partially refracted and reflected by the scratches or foreign matter. On the other hand, for light in the invisible light region (invisible light), at the places where scratches have been formed in or foreign matter has adhered to the photographic film, the transmitted light amount varies, but the invisible light is not affected by the density of the image recorded on the photographic film.
Accordingly, in accordance with the technique described in the aforementioned publication, a scratch in or foreign matter on the photographic film can be detected from changes in the transmitted light amount of invisible light, and changes in the transmitted light amount of light in the visible light range that are due to the scratch in or the foreign matter on the photographic film can be corrected. Namely, the defective portions of the image (i.e., of the image as represented by image information obtained by reading in the visible light region), which defective portions are due to a scratch in or foreign matter on the photographic film, can be corrected.
However, among the many types of photographic films which are currently on the market, there are photographic films which are sensitive to invisible light as well, and on which, at the time of exposure and recording of an image, an invisible light image is simultaneously formed (so-called image-copy) in addition to the visible light image. In such a photographic film, the transmitted light amount of invisible light varies in accordance with the density of the image of invisible light. Thus, even if invisible light is used as above, it is difficult to isolate changes in the transmitted light amount which are due to the recorded image, and changes in the transmitted light amount which are due to a scratch or foreign matter. Problems arise in that, by carrying out the above-described defect detection-correction processing, conversely, deterioration in the image quality arises, such as edge portions in the image becoming more dull and the like, and the defect correction processing requires an unsuitably long time.
The aforementioned problems are not limited to cases in which defect detection-correction is carried out at the time of exposing and recording onto a photographic film for images which are formed at the same time as images by invisible light. The same types of problems arise in other cases; for example, in the reading of an image which is recorded on a reversal film which is set in a slide mount, by carrying out reading in a state in which non-image portions, such as the slide mount or the like, are within the reading range, the non-image portions (the portions corresponding to the slide mount) are included in the image represented by the image data which is the object of processing.